keel / draft questions
In the 28 to 32 ft range there is a whole lot of differences as has been noted above. For only 4 ft of length it takes in a lot of boat variations in as many ways as possible. The price range can scare you too.
As to when coatal becomes offshore it''s more the definition of the certification than anything else. Offshore does require certain skills and knowledge you don''t have certification to yet (even if you know it). Much of it is operational systems and navigation since a cruising boat has more systems that need to be understood. There are a few more sailing skills but the basics still remain. Currently it is assumed that in any serious event you are close to shore and can come back to shore easily. You could navigate mostly visual. That would not be true half way on a on a trip to Catalina and suddenly something happens. Sailing halfway back with some serious problem might require skills than you have certified for.
As to just a boat to make Catalina in goes, the diplacemnt requirements for such a trip is not large. You won''t be carrying tons of provisions. Higher displacement carries more stuff. You don''t have a lot of requirements for say a 3 day weekend. It''s like any trip if you left for a month you need a lot more stuff. You need more displacemnt from the volume of what you''ll need. Tanks full of fuel and water will add a lot of weight.
There is no short list of boats that would do that for you. That''s the good news. The list would be quite long. The experience and skills to do it safe is the part you need most now. On a good day with some luck you probably could do it. But that would not be safe or smart.
Going out on other peoples boats is what to do. Sail lots of boats if you can. It makes your choices a lot easier when you know what they do and what they feel like. You grow to like certain things partly from understanding and partly from just things you like.
There is what you could do it in and what you feel best doing it in. They are not the same. You want a boat you feel great in that is right for you and your skill level.